Fri 15 May

Friday 13 May:

Key Concept(s) Today: Inductance

L#82: 1- 4, 7, 10 - 14, 17, 19

(due Friday (13 May) (Mag Fields)

Monday May 16th Gliders:

Made out of Paper
Who's glider goes the farthest?

L#85: 2, 4, 7 - 9, 11, 12, 14, 15, 19

(due Tues (17 May) (Inductance)

L#86: 7, 8, 11

(L#87): 3, 11, 14

(due Wed (18 May) (Magnets)

Video:

http://www.youtube.com/results?search_query=physics+mysteries&aq=0

Thurs May 19: Review

(L# 78, 79, 81, 82, 85, 86)

Test Friday 20 May L# 78, 79, 81, 82, 85, 86

Egg Bungee (Mon 23 May)

L#90: 1, 2, 8, 9, 12, 14, 15, 20

(EM Radiation) Tues 24 May

Wed - Fri 25-27 May (DEMO's)

Thurs 26 May 1/2 day

Fri 27 May: Auto Safety

Wed 1 Jun Review for final

Final: Thurs & Fri 2 & 3 June

Mon & Tues 6 & 7 June (Sub)

Mouse Trap Car Thurs 9 June

L#91: 1, 2, 4, 5, 12 - 15, 20

(EM Radiation) Wed 8 Jun

L#93/95/96 (Relativity) (non-Sr's)

#93:1 - 3, 17, 18 #95: 1, 2, 6

#96: 1, 2, 5, 7

(due Fri 10 Jun)

#98 (Half-Life): 1 - 4, 6, 7, 10, 14, 16, 19, (due Mon 13 June)

Magnet Demo

Two right hand rules (“+” flow/charge)

1. To create a magnetic field from a current (many moving charges). Thumb = direction of “+” current

Curl of finger tips = Direction of Field

2. To create a force on a moving charge in an existing magnetic field.

Back of Hand/Index finger = Direction of motion of “+” charged particle

Direction of finger tips =

Direction of Field

Direction of Thumb =

direction of Force

What is the force on the wire below?

Which way is the electron moving (CCW or CW)?

Magnets have two poles (N and S)

Magnetics are normally permanent (primary iron, cobalt and nickel) that are caused by alignment of the domains. Or electromagnetic (caused by moving charges).

1. Wires affect each other because of creation of magnetic field and the force of a moving charge in a magnetic field.

a. What does the magnetic field look like between the wires?

b. What will happen to the two wires in the case below?

c. What will happen to the two wires if the current flows in the opposite direction?

1. (a) X's from left wire (b) (c)

dot's from right wire

2. a. In both I and II, the magnetic fields B are decreasing with time. What is the direction of induced current in both cases?

b. In both I and II, the magnetic fields B are increasing with time. What is the direction of induced current in both cases?

c. In both I and II, the wire loops are being pulled across the uniform magnetic fields with a constant velocity. What is the direction of induced current in both cases

d. In both I and II, the wire loops are being flattened (smaller area). What is the direction of induced current in both cases?

http://www.physics.uoguelph.ca/applets/Intro_physics/kisalev/java/indcur/index.html

I II

(A) Counterclockwise (A) Clockwise

(B) Clockwise (B) Counterclockwise

(D) Counterclockwise (D) Clockwise

3. Two circular coils are situated perpendicular to the z-axis as shown above. There is a current in the primary coil. What is the direction of current in the Secondary Coil in each of the following?

(A) Increasing the current in Primary

(B) Decreasing the current in Primary

(D) Moving the secondary coil closer to the primary coil

(E) Decreasing the cross‑sectional area of the secondary coil

(F) Rotating the secondary coil about the z-axis

(A) Clockwise

(B) Counterclockwise

(D) Clockwise

(E) Counterclockwise

(F) No current clockwise or counterclockwise, inside part of the ring gets higher in potential and outside gets lower

4. The figure above shows a rectangular loop of wire of width l and resistance R. The entire loop starts out over the magnetic field. Then, the loop is pulled to the right at a constant speed v. What is the direction of the induced current in the loop as: a. it travels across the field? b. as it leaves the field

a. No current: field (DX's) not changing.

b. As soon as the loop reached the edge, it loses loses X’s. The loop produces a clockwise current to counter the loss of X’s (produce more X’s).

5. There is a counterclockwise current I in a circular loop of wire situated in an external magnetic field directed out of the page as shown above. The effect of the forces that act on this current is to make the loop?

Expand the loop

I Y

x x x

Z x x x x x x

x x x x x x

x x x

2. In the diagram above, loop “Z” has a steady current that is producing the X’s shown.

a. What is the direction of the current in loop Z?

b. What is the direction of the induced current in loop Y?

C. If the current (I) starts to decrease in loop “Z”, what is the direction of the induced current in loop radius “Y”.

a. Clockwise

b. No induced current (no change)

c. Decrease in “dots”, so directions will be counterclockwise to oppose the loss.

What is the direction of force to the charged particles below?

1. 2.

+ -

(Direction of Current I)

3. + 4 + 5. -

Positive charge going into paper

Direction of the force on the charged particle for questions

c. d. e. None of the above

Film

http://www.learnoutloud.com/Free-Audio-Video/Education-and-Professional/Teaching/The-Wonders-of-Electricity-and-Magnetism/22079